Usefull Unix/Linux commnads

1) To find a "word" or pattern in all files in a directory & subdirectories
find . -name "*" -exec grep -l {} \; -print
Example: belowsearching for word
find . -name "*" -exec grep -l dba {} \; -print

2)To find a class inside a set of Jar files
for i in 'find .-name *.jar'
do
if test 'jar -tvf $i|grep QualityObject.class'
then
ls $i
fi
done

3) To unzip all the patches in 1 directory in one go
for i in *.zip
do
unzip $i
done

4)To find the symbolic links that point to the old path in your oracle_home and appl_top.
This command is useful in cloning after restore from source to target that symbolic link are not pointing to source.
ls -al `find . -type l` | grep $OLD_PATH

5)To find all the text files that contains the old path at the UNIX level.
find . -type f -print|grep -v ":"|xargs file|grep "text"|awk '{FS=":"}{print $1}'|xargs grep -il $OLD_PATH

6) To Sort files based on Size of file in a Directory
Useful in finding out spaces issues
ls -l | sort -nrk 5 | more

7)How to check if a Port is listening for any Service
netstat -an | grep $PORTNO